@article{Chen:2021cw,
  author = "Chen, Xu",
  title = "{A northern sky survey for ultra-high-energy gamma-ray source using the Tibet air-shower array and muon-detector array.}",
  doi = "10.22323/1.395.0880",
  journal = "PoS",
  year = 2021,
  volume = "ICRC2021",
  pages = "880"
}